Implantable self-cleaning blood filters

ABSTRACT

A blood filter device having occlusion-resistant characteristics. The occlusion-resistant characteristics decrease the likelihood of the filter being blocked by thrombi. The filter device includes at least one anchor portion for anchoring the filter device within one or more arteries, and a filter portion for filtering thrombi from the blood entering the artery. In some embodiments, an anchor portion is capped with a filter cap. In various embodiments, the filter cap is protrudes into the aorta to promote occlusion resistance. In one embodiment, the device can be modified in situ to re-establish normal blood flow through the artery in the unlikely case of thrombotic or other blockage of the filter. In some embodiments, a bypass opening or open channel defining an access port is provided to accommodate passage of surgical instruments into the artery and to enable blood flow to bypass the filter should the filter become heavily occluded.

RELATED APPLICATIONS

This patent application is a continuation application of U.S. patentapplication Ser. No. 16/239,427, filed Jan. 3, 2019, which is acontinuation of U.S. patent application Ser. No. 15/311,398, filed Nov.15, 2016, which is a National Phase entry of PCT Application No.PCT/IB2015/001206, filed May 14, 2015, which claims the benefit of U.S.Provisional Patent Application No. 61/994,276, filed May 16, 2014, andof U.S. Provisional Patent Application No. 62/029,044, filed Jul. 25,2014. The disclosures of the above referenced related applications arehereby incorporated by reference herein in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure is directed generally to implantable blood filterdevices and more specifically to filter devices to protect the brain andother organs from emboli.

BACKGROUND OF THE DISCLOSURE

Various conventional devices exist to contain or control the flow ofthrombic material and atheroma debris. Examples of such devices includeU.S. Pat. Nos. 6,712,834 and 6,866,680 to Yassour, et al., and U.S. Pat.No. 7,670,356 to Mazzocchi et al., which disclose blood filter devicesdesigned to capture the debris material. A concern with capture filtersis that they can foul to the extent that blockage of blood flowdevelops, with obvious consequences. Accordingly, these devices aretypically unsuitable for long term or permanent implantation.

In another approach, U.S. Pat. No. 6,258,120 to McKenzie et al., U.S.Pat. No. 8,430,904 to Belson, U.S. Pat. No. 8,062,324 to Shimon et al.,and U.S. Patent Application Publication No. 2009/0254172 to Grewe aredirected to aortic diverters that divert emboli away from arteries.Diverter-type devices are limited to certain artery junction structureswhere flow diversion is a suitable substitute for filtering, and, inmany instances, do not provide a positive barrier to emboli, either bydesign or because of the way they are mounted within the aorta.Furthermore, these devices can foul with debris build up over time,leaving no recourse for remedying the fouling, and so are not suitablefor long term or permanent implantation. Also, diverter devices that arebased on anchoring in the aorta require large diameter catheters fordelivery. Other diverter-type devices include U.S. Pat. No. 8,460,335 toCarpenter, are held in place by the attendant deployment means, and thussuitable only for temporary service.

A blood filter device that overcomes the aforementioned shortcomings ofconventional blood filters and aortic diverters would be welcomed.

SUMMARY OF THE DISCLOSURE

In various embodiments, a blood filter device is disclosed that combinesthe advantages of a positive blood filter device with the diversionaryadvantages of aortic diverters to provide a blood filter device that isocclusion-resistant. In some embodiments, the blood filter device issuitable for either temporary filtering or permanent or long termfiltering. In one embodiment, the blood filter device can be withdrawnfrom the artery using a percutaneous technique. In some embodiments, thedevice can be reconfigured or opened up in situ to re-establish normalblood flow through the artery in the unlikely case of thrombotic orother blockage of the filter.

In some embodiments, the disclosed blood filter is inserted into theostium (take-off) of the major body artery, e.g., a branch of the aortato filter the blood flowing into this artery from the aorta. In oneembodiment, the device is designed in a way that, when inserted into theostium of the branch of the aorta, a filter cap of the device is locatedin the same geometrical plane as the take-off (ostium) of the artery. Inother embodiments, the filter cap protrudes into the lumen of the aorta.The projection of the filter cap into lumen of the aorta enablesself-cleaning of the filter cap by the aorta blood flow that effectivelypurges the filtering surface of thrombi and atheroma debris and preventsthe filter cap from being blocked by such emboli. This preserves thepatency of the filter. In certain embodiments, the blood filter providesa physician with a capability of opening the filter in situ and withminimal invasiveness in the event that the filter cap becomessignificantly blocked by thrombi and/or debris and/or other embolicmaterial.

In various embodiments, the occlusion resistant aspects of the bloodfilter device is also augmented by the orientation of the filtering caprelative to the direction of the blood flow. The filter cap of thefilter device is located upstream of the anchor portion, as comparedwith prior art devices where filter is located downstream of a stent. Inaddition, certain embodiments implement a convex surface that bows inthe direction of the blood flow, whereas other prior art filters presenta concave surface relative to blood flux.

In various embodiments, the filter device defines both a coarse porosityand a fine porosity. The coarse porosity can promote tissue ingrowth foranchoring of permanently implanted devices; the fine porosity issuitable for the filtering function.

In some embodiments, a filter device is configured to be inserted in oneartery and oriented to cover an ostium of a second adjacent artery.Optionally, various embodiments are configured to be inserted into bothostia of the adjacent arteries, with a tubular filter portion beingsupported therebetween. Such filter devices provide filtering ordiversionary protection from incursion of thrombi and atheroma debris tothe adjacent arteries.

The blood filter device of various embodiments can be left in an aorticbranch take-off for a short period of time (hours, days, or weeks) incase of acute interventional procedure such as percutaneous aortic valvereplacement (TAVI), heart or aortic surgery, AF ablation procedure, andtreatment of infectious endocarditis. For short-term uses, the devicecould be withdrawn using percutaneous technique at a physician'sdiscretion after implantation. Optionally, some embodiments can beutilized as a permanent implant in patients posing a chronic risk ofembolic complications such as atrial fibrillation, degenerative andautoimmune valvular disease, atheromatous disease of aorta, patentforamen ovale or recurrent stroke of unknown origin.

Various embodiments of the disclosed filter device can be put into anybranch of the aorta, including brachiocephalic arteries, as well asrenal, and mesenteric arteries.

Structurally, various embodiments of a blood filter for filtering bloodentering an artery are disclosed, comprising a body that includes ananchor portion defining a flow outlet port at a first end of the bodyand including a porous wall that defines a first porosity, and a filterportion that extends from the anchor portion and includes a porous wallthat defines a second porosity, the second porosity being less than thefirst porosity. In one embodiment, the filter portion defines a secondend of the body, the second end defining a bypass aperture.

In some embodiments, the body defines a straight cylinder. Optionally,the blood filter comprises one of a flange and a plurality ofprotrusions extending laterally outward from the body. In someembodiments, the one of the flange and the plurality of protrusions aredisposed proximate a junction between the anchor portion and the filterportion.

In other embodiments, the body defines a curved cylinder about a curvedbody axis. Optionally, a first tangential portion of the filter portiondefines the second porosity, and a second tangential portion of thefilter portion defines the first porosity. In one embodiment, the bypassaperture lies substantially on a plane, and the curved body axisintersects the plane at an acute angle. Various embodiments optionallyinclude a centering hook structure coupled to the anchor portion thatprojects laterally outward from the anchor portion.

In various embodiments of the disclosure, a filter cap is coupled to thefilter portion. A maximum lateral dimension of the filter cap can beless than or equal to a diameter of the body, with the filter cap beingplanar. For some embodiments, the filter portion defines a lateralbypass aperture. Optionally, the blood filter further comprises a shroudsurrounding the lateral bypass aperture.

In various embodiments, the filter cap is bulbous. Optionally, thefilter cap also includes a hub that is removable for defining an openconfiguration of the blood filter, the open configuration enabling bloodto flow through the anchor portion unfiltered. Optionally, the filtercap defines a bypass aperture. In one embodiment, the anchor portion isconcentric about a central axis, and the bypass aperture defines anormal vector having a lateral component relative to the central axis.In one embodiment, the filter cap includes a cover that covers thebypass aperture, the cover being removable for selective access to theblood filter through the bypass aperture. Optionally, the cover includesa hub. In various embodiments, the filter cap and the body are unitary.In some embodiments, the body includes a flange portion, the bulbousportion being configured to register against the flange portion.Optionally, the flange portion and the body are unitary. In certainembodiments, a stem portion extends from the bulbous portion, the stemportion being dimensioned for removable insertion into the body.Optionally, the stem portion and the bulbous portion are unitary.

In various embodiments of the disclosure, a dual anchor configuration isdisclosed, wherein the body further comprises a second anchor portiondefining a second flow outlet port and including a porous wall thatdefines a third porosity. The third porosity can be configured to besubstantially the same as the first porosity. In one embodiment, theanchor portion is dimensioned for anchoring to an innominate artery andthe second anchor portion is dimensioned for anchoring to a left carotidartery. Optionally, the anchor portion defines a first diameter, thesecond anchor portion defines a second diameter, the second diameterbeing less than the first diameter.

The filter portion of the dual anchor embodiments can also define alateral bypass aperture. Optionally, the filter comprises a shroudsurrounding the lateral bypass aperture. In various embodiments, thesecond anchor portion extends from a second end of the filter portion,the second end of the filter portion being opposed to the first end ofthe filter portion. In some embodiments, the filter portion isconfigured to define a U-shape in an implanted configuration wherein thefilter portion is inferior to both the anchor portion and the secondanchor portion in the implanted configuration. Optionally, all of theU-shape has the second porosity.

For various embodiments, the filter portion is dimensioned to extendfrom an ostium of an innominate artery to cover an ostium of a leftcarotid artery. The anchor portion can be concentric about a centralaxis, with the filter portion including an elbow-shaped portion andextending lateral to the anchor portion to define a lateral dimensionreferenced from the central axis, the lateral dimension being in a rangeof 20 mm to 60 mm inclusive; in some embodiments, in a range from 20 mmto 40 mm inclusive; in some embodiments, in a range from 20 mm to 35 mminclusive. (Herein, a range that is said to be “inclusive” includes theendpoint values of the stated range.) In some embodiments, the filterportion defines a diameter in a range of 6 mm to 20 mm inclusive; insome embodiments, in a range from 8 mm to 18 mm inclusive; in someembodiments, in a range from 10 mm to 15 mm inclusive.

In various embodiments, the body portion comprises one of abio-absorbable alloy and a bio-absorbable polymer. Optionally, the bodyportion comprises a material selected from the group consisting ofstainless steel, platinum, platinum-iridium alloys, nickel-cobaltalloys, nickel-titanium alloys, magnesium based alloys, polyethyleneterephthalate, polyurethane, and polylactic acid based polymers.

In some embodiments, the porous wall of the filter portion defines aporosity in the range of 50% to 98% inclusive; in some embodiments, in arange from 60% and 95% inclusive; in some embodiments, in a range from70% and 95% inclusive; in some embodiments, in a range from 75% and 90%inclusive. In some embodiments, the porous wall of the anchor portiondefines a porosity in the range of 60% to 98% inclusive; in someembodiments, in a range from 70% and 95% inclusive; in some embodiments,in a range from 75% and 95% inclusive; in some embodiments, in a rangefrom 80% and 95% inclusive. Optionally, the porous wall of the body is ameshed structure. The porous wall of the filter portion can also beconfigured as a meshed structure. Optionally, the filter portion definespore sizes in a range from 40 μm to 1000 μm inclusive; in someembodiments, in a range from 300 μm to 1000 μm inclusive; in someembodiments, in a range from 400 μm to 800 μm inclusive; in someembodiments, in a range from 400 μm to 600 μm inclusive; in someembodiments, in a range from 600 μm to 800 μm inclusive; in someembodiments, in a range from 500 μm to 700 μm inclusive.

Various embodiments of a filter device disclosed herein include a bodycomprising a porous wall and having a proximal end and a distal end anddefining a body axis that passes through the proximal end and the distalend. A filter cap is operatively coupled to the proximal end of thebody, the filter cap being either planar or convex relative to the bodyaxis in a direction that extends away from the body. The body canoptionally define a radial dimension that is larger than a nominaldimension of an artery designated for implantation. In one embodiment,the body includes an anchor portion that comprises a shape memorymaterial.

In some embodiments, the proximal end of the porous wall is configuredto filter blood passing therethrough. By configuring the proximal end asa filter, an increased margin of tolerance is realized for placement ofthe device. That is, absolute registration of the filter cap at allpoints on the circumference of the ostium is not required to achieve thefull effect of filtering and/or diversion.

In various embodiments, the filter cap includes a bulbous portion andcan also include a hub portion. In one embodiment, removal of the hubportion configures the filter device in an open configuration wherebythe filter cap is open to enable blood flow through the body unfiltered.In another embodiment, the filter cap is detachable from the body toconfigure the filter device in an open configuration whereby the filtercap is open to enable blood flow through the body unfiltered. The hubportion can include a disc portion that is seated within the bulbousportion. In some embodiments, the bulbous portion is resilient. In oneembodiment, the hub portion is replaceable.

In various embodiments of the disclosure, a blood filter is disclosedcomprising a body that includes: an anchor portion including a first endthat defines a flow outlet port, the flow outlet port being normal to abody axis, the anchor portion including a first porous wall; and afilter portion that extends from the anchor portion, the filter portionincluding a second porous wall and defining a lateral bypass apertureproximate a second end of the body. Optionally, the filter portionincludes an elbow portion the second end of the body, the elbow portiondefining the lateral bypass aperture. Optionally, the filter portionincludes an extension portion that extends laterally from the elbowportion, the extension portion defining the lateral bypass aperture.Optionally, the first porous wall and second porous wall are ofsubstantially equal porosity; alternatively, the first porous walldefines a first porosity, the second porous wall defines a secondporosity, the first porosity being greater than the second porosity. Inone embodiment, the first porosity defines a first average pore size,and the second porosity defines a second average pore size, the secondaverage pore size being less than the first average pore size.

In various embodiments of the disclosure, a blood filtering system isdisclosed, comprising a plurality of filter devices, each including abody. Each body includes an anchor portion defining a flow outlet portat a first end of the body, the outlet port being normal to a firstaxis, the anchor portion including a porous wall. A filter portionextends from the anchor portion, the filter portion including a porouswall and defining a bypass aperture at a second end of the body, thebypass aperture being normal to a second axis, the second axis defininga non-zero angle with respect to the first axis. In some embodiments,the non-zero angle of each of the plurality of filter devices is in arange from 60° and 120° inclusive. In certain embodiments, the non-zeroangle of each of the plurality of filter devices is substantially 90°.Optionally, the filter portion of each of the plurality of filterdevices includes an elbow-shaped portion that depends from the anchorportion, the elbow-shaped portion defining the bypass aperture.Optionally, each of the plurality of filter devices includes anelbow-shaped portion that depends from the anchor portion and anextension portion that extends from the elbow-shaped portion, theextension portion defining the bypass aperture. For various embodiments,the bypass aperture is centered on the second axis at a distance in arange of 20 mm to 60 mm inclusive from the first axis. For someembodiments, the bypass aperture is centered on the second axis at adistance in a range of 6 mm to 10 mm inclusive from the first axis.Optionally, the porous wall of the anchor portion of each of theplurality of filter devices defines a first average pore size, and theporous wall of the filter portion of each of the plurality of filterdevices defines a second average pore size, the second average pore sizebeing less than the first average pore size.

In various embodiments, a slot is defined on a superior face of thefilter portion, the filter portion thereby defining a channel opening ata lateral end of the filter portion. The slot extends through theelbow-shaped portion and into the anchor portion.

In another embodiment of the disclosure, a method for filtering bloodflowing into an artery is presented. The method can comprise one or moreof the following:

-   -   providing a filter device having an body and a filter cap, the        body comprising an anchor portion having a porous wall, a        proximal end, and a distal end, the body defining a body axis        that passes through the proximal end and the distal end, the        filter cap being operatively coupled to the proximal end of the        body, the filter cap being either planar or convex relative to        the body axis in an upstream direction;    -   disposing the filter device in the artery so that the filter cap        is upstream of the anchor portion;    -   positioning the filter cap in a geometrical plane defined by an        ostium of an artery;    -   positioning the filter cap in an upstream direction from a        geometrical plane defined by an ostium of an artery, such that a        wall portion of the proximal end of the body filters blood        passing therethrough;    -   removing the hub portion to open the filter cap, for example by        unscrewing the hub from the filter cap;

The filter cap provided in the step of providing a filter device cancomprise a meshed structure. In one embodiment, the meshed structure isa flat mesh.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a frontal cutaway view of a human heart with a filter deviceimplanted in an embodiment of the disclosure;

FIG. 1A is an enlarged, schematic view of the filter device of FIG. 1 inan implanted configuration in an embodiment of the disclosure;

FIG. 1B is a perspective, distal end view of the filter device of FIG.1A in isolation;

FIG. 1C is a is a perspective, proximal end view of the filter device ofFIG. 1A in isolation;

FIG. 1D is an enlarged, partial view of FIG. 1B in an embodiment of thedisclosure;

FIG. 2 is a schematic view of a filter device in an implantedconfiguration in an embodiment of the disclosure;

FIG. 2A is a perspective view of a filter device having a porosity thatvaries axially in an embodiment of the disclosure;

FIG. 3 is a sectional view of a filter device in an implantedconfiguration, the filter device having a porosity that variestangentially in an embodiment of the disclosure;

FIG. 3A is a perspective, distal end view of the filter device of FIG. 3in isolation;

FIG. 4 is a schematic view of a filter device having a convex filter capin an implanted configuration in an embodiment of the disclosure;

FIG. 5 is a perspective view of a filter device having lateralprotrusions in an implanted configuration in an embodiment of thedisclosure;

FIG. 6 is a perspective view of a filter device having a bulbous filtercap in an implanted configuration in an embodiment of the disclosure;

FIG. 7 is a perspective view of the filter of FIG. 6 in an openconfiguration;

FIGS. 8A through 8F are perspective views of a fabrication of filterdevices having bulbous filter caps in embodiments of the disclosure;

FIG. 9 is a perspective view of a detachable bulbous filter cap in anembodiment of the disclosure;

FIG. 10 is a perspective, exploded view of a detachable, replaceablebulbous filter cap having a stem portion in an embodiment of thedisclosure;

FIG. 11 is a perspective view of a bulbous filter device having aremovable hub with a disc portion in an embodiment of the disclosure;

FIG. 12 is a sectional view of a bulbous filter device having aremovable, replaceable hub having a disc portion in an embodiment of thedisclosure;

FIG. 13 depicts the bulbous filter device of FIG. 12 in an implantedconfiguration with the removable, replaceable hub and disc removed;

FIG. 14 is a cutaway perspective view of a straight cylinder filterdevice in an implanted configuration with a bypass aperture at aproximal end in an embodiment of the disclosure;

FIG. 15 is a cutaway perspective view of a filter device in an implantedconfiguration the filter device including a convex filter cap and havinga lateral bypass aperture in an embodiment of the disclosure;

FIG. 16 is a cutaway perspective view of a filter device in an implantedconfiguration the filter device including a bulbous filter cap andhaving a lateral bypass aperture in an embodiment of the disclosure;

FIG. 17 is a cutaway perspective view of a filter device in an implantedconfiguration the filter device defining a curved cylinder with alateral bypass aperture in an embodiment of the disclosure;

FIG. 17A is a perspective view of the implanted filter device of FIG. 17in isolation;

FIG. 18 is a cutaway perspective view of a filter device in an implantedconfiguration, the filter device defining a curved cylinder with alateral bypass aperture in an embodiment of the disclosure;

FIG. 18A is a perspective view of the implanted filter device of FIG. 18in isolation;

FIG. 19 is a cutaway perspective view of a filter device in an implantedconfiguration, the implanted filter device defining a curved cylinderthat defines a lateral bypass aperture and having a porosity that variestangentially in an embodiment of the disclosure;

FIG. 19A is a perspective view of the implanted filter device of FIG. 19in isolation;

FIG. 19B is a perspective view of the filter device of FIG. 19 withoptional centering hook in an embodiment of the disclosure;

FIG. 20 is a cutaway perspective view of a filter device in an implantedconfiguration, the filter device defining a curved cylinder with a slotand channel in an embodiment of the disclosure;

FIGS. 20A and 20B depict the filter device of FIG. 20 with differingslot lengths in embodiments of the disclosure;

FIG. 21 is a perspective view of a detached centering hook in anembodiment of the disclosure;

FIG. 22 is a sectional view of a dual anchor filter device in animplanted configuration in an embodiment of the disclosure;

FIG. 22A is a perspective view of the implanted dual anchor filterdevice of FIG. 22 in isolation;

FIG. 22B is a perspective view of the dual anchor filter device of FIG.22A in a fully expanded configuration prior to implantation in anembodiment of the disclosure;

FIG. 23 is a perspective view of a fully expanded dual anchor filterdevice having anchor portions of different diameters in an embodiment ofthe disclosure;

FIG. 24 is a sectional view of a dual anchor filter device with alateral bypass aperture in an implanted configuration in an embodimentof the disclosure;

FIG. 24A is a perspective view of the dual anchor filter device of FIG.24 in the implanted configuration in isolation;

FIG. 25 is a sectional view of a dual anchor filter device with ashrouded bypass aperture in an implanted configuration in an embodimentof the disclosure;

FIG. 25A is a perspective view of the dual anchor filter device of FIG.25 in the implanted configuration in isolation;

FIG. 26 is a sectional view of a double filter arrangement in anembodiment of the disclosure; and

FIGS. 26A through 26D is a sectional view of alternative double filterarrangements in embodiments of the disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIGS. 1 through 1D, a filter device 20 is depicted in animplanted configuration 22 and in isolation in an embodiment of thedisclosure. The filter device 20 is depicted as being implanted in theostium 24 (take-off) of an artery 26, and more specifically into abranch 28 of an aortic arch 32 to filter the blood flowing into theartery 26 from the aortic arch 32. The artery 26 can be characterized ashaving an effective flow radius 34 relative to a central flow axis 36.The FIG. 1 depiction also presents, without limitation, variouscandidate arteries for implantation of the filter device 20, includingthe innominate artery (and attendant right carotid and right subclavianarteries), the left carotid artery, and the left subclavian artery. TheFIG. 1 depiction also identifies a superior direction 30 and an inferiordirection 31 of the anatomy.

The filter device 20 includes a body 46 and a filter cap or element 44.In one embodiment, the body 46 includes a porous wall 48 having an innersurface 52, an outer surface 54, a proximal end 56 and a distal end 58,the distal end 58 defining an opening 62 that serves as a flow outletport 64. (Herein, “proximal” and “distal” are relative terms that refergenerally to the direction of blood flows, with proximal being generallyupstream from distal.) In various embodiments, the flow outlet port 64is open, i.e., does not include a filtering medium that transverses thebody axis 66. In one embodiment, the proximal end 56 of the body 46 iscapped by the filter cap 44. The body 46 defines a body axis 66 thatpasses through the proximal and distal ends 56 and 58 of the body 46.The outer surface 54 defines a maximum outer radial dimension 68relative to the body axis 66. In one embodiment, the body 46 iseffectively a stent, comprising a meshed structure 72 that can besubstantially cylindrical in shape, as depicted. In various embodiments,the body is dimensioned to provide an interference fit between anarterial wall 74 and the body 46 when in an expanded state to anchor thefilter device 20 in the implanted position. Optionally, the body 46 canbe balloon expandable or self-expanding.

The filter cap 44 can comprise a substantially planar disc 74 thatcovers the proximal end 56 of the body 46. In one embodiment, the filtercap 44 is unitary with the proximal 56 end of the body 46. Herein, a capthat is “unitary” with the body is integrally formed with the body,without need for a separate connection step to secure the cap to thebody. Alternatively, the filter cap 44 can be formed as a separatecomponent that is then joined to the body, for example using mechanicalconnections or with an adhesive or by a fusion or welding process. Invarious embodiments, the filter cap 44 comprises a meshed structure 76.

The meshed structures 72, 76 of the body 46 and the filter cap 44, whenutilized, can be a flat mesh 78, as depicted in FIG. 1D. The flat mesh78 can be comprised of a web 80 of cross-members 82 formed of asubstantially sheet-like structure 86 and that define a plurality ofopenings 84 in a matrix arrangement. The flat sheet structure can berolled into the cylindrical shape either before or after the formationof the openings 84. Alternatively, instead of a flat sheet, the openings84 can be formed in a hollow cylinder to provide a uniform bodythickness (i.e., no overlap). The plurality of openings 84 can berectangular in shape, as depicted in FIG. 1D, each opening 84 beingsurrounded and defined by adjacent cross-members 82 of the web 80, andsuch that the cross-members 82 intersect at substantially right angles.Other geometries for the openings 84 and cross-members 82 are alsocontemplated, including but not limited to parallelograms (i.e., wherecross-members intersect at non-right angles) or circular aperturesformed in the sheet-like structures 86. The openings 84 of the flat mesh78 can be formed by techniques available to the artisan, such as lasermachining, electro-discharge machining (EDM), or mold injectionstechniques. Alternatively, the meshed structures 86 can comprise a wovenmesh (not depicted), wherein the cross-members 82 comprise interwovenstrands.

The meshed structures 86 can be characterized by mesh sizing parametersthat can include the number of cross-members 82 per lineal length, aprojected width of the cross-members (defined as the width of thecross-member as projected in a direction normal to the meshedstructures), and/or an open fraction (defined as the open area of themeshed structure per unit area of meshed structure). A non-limitingexample of the mesh sizing parameters suitable for the anchor portion 42of some embodiments of the present disclosure include pore sizes in arange from 500 μm to 5000 μm inclusive; in some embodiments, in a rangefrom 500 μm to 3000 μm inclusive; in some embodiments, in a range from800 μm to 2000 μm inclusive; in some embodiments, in a range from 800 μmto 1500 μm inclusive; in some embodiments, in a range from 1000 μm to1500 μm inclusive. A non-limiting example of the mesh sizing parameterssuitable for the filtering portion 110 of some embodiments of thepresent disclosure include pore sizes in a range from 40 μm to 1000 μminclusive; in some embodiments, in a range from 300 μm to 1000 μminclusive; in some embodiments, in a range from 400 μm to 800 μminclusive; in some embodiments, in a range from 400 μm to 600 μminclusive; in some embodiments, in a range from 600 μm to 800 μminclusive; in some embodiments, in a range from 500 μm to 700 μminclusive. In some embodiments, the open fraction of the anchor portion42 and/or the filter portion 110 is in a range from 50% and 95%inclusive; in some embodiments, in a range from 60% and 90% inclusive;in some embodiments, in a range from 70% and 90% inclusive; in someembodiments, in a range from 75% and 85% inclusive. In embodimentsemploying cross-members 82 of substantially uniform width, anon-limiting example of the projected width of the cross-members 82 isbetween 40 μm to 1000 μm inclusive; in some embodiments, in a range from300 μm to 1000 μm inclusive; in some embodiments, in a range from 400 μmto 800 μm inclusive; in some embodiments, in a range from 400 μm to 600μm inclusive; in some embodiments, in a range from 600 μm to 800 μminclusive; in some embodiments, in a range from 500 μm to 700 μminclusive. For embodiments implementing woven strand meshed structures,the projected width of the cross-members is taken as the diameter of thewoven strands.

The porous wall 48 and/or filter cap 44 can be characterized as having a“porosity.” Herein, “porosity” is defined as the ratio of the voidvolume to the total volume of a representative sample of the medium. Formeshed structures 86, the total volume of a unit area of mesh is definedby the overall thickness of the unit area of the meshed structure 86multiplied by that unit area. The void volume is the volumecomplementary to the volume of the cross-members 82 per unit area ofmeshed structure 86 (i.e., the volume not occupied by the cross-members82 of the meshed structure 86 per unit area). In addition to meshstructures, “porosity” also describes open cell structures, which canalso be utilized for the porous wall 48 and/or various filter caps.

The anchor portion 42 and/or filter cap 44 can include one or several ofa number of materials available to the artisan, including metals (e.g.,stainless steel, platinum, platinum-iridium alloys, nickel-cobaltalloys, nickel-titanium alloys (e.g., NITINOL), and bio-absorbablealloys such as magnesium based alloys) and various polymers (e.g.,polyethylene terephthalate (PET), polyurethane, and bio-absorbablepolymers such as polylactic acid based polymers).

In use, in various embodiments, the filter device 20 is inserted intothe ostium 24 (take-off) of the artery 26, and more specifically intothe branch 28 of the aortic arch 32 to filter the blood flowing into theartery 26 from the aortic arch 32, as depicted in FIG. 1A. In oneembodiment, the filter device 20 is designed in a way that, wheninserted into the ostium 24 of the branch 28 of the aortic arch 32, thefilter cap 44 is located in the same geometrical plane as the take-off24 of the artery 26.

In various embodiments, the body 46 includes an anchor portion 42. Theanchor portion 42 is so-named because it is configured to anchor thebody 46 to the artery 26. In some embodiments, the anchor portion 42 isthe same length as the body 46; that is, the entire body 46 can beconfigured as an anchor portion 42. In various embodiments, the anchorportion 42 comprises an elastic material such as cobalt-chromium-nickelalloys (e.g., ELGILOY), platinum-iridium alloys or nickel-titaniumalloys. In this case the device could be seated in the artery using theself-expanding force of the elastic material. In other embodiments, theanchor portion 42 can be comprised of a material such as stainless steelor cobalt-chromium alloys and can be deployed using the plasticdeformation of those materials. In this case the device could bedelivered into the artery using expansion balloon (like a balloonexpandable stent). In some embodiments, the anchor portion 42 iscomprised of a material that is pliable but having substantial “shapememory” (i.e., having a tendency to return to its original shape afterdeformation). Materials having these characteristics include certainalloys such as nickel-titanium. In other embodiments, the anchor portion42 can be comprised of a material that is pliable but has little or noshape memory. Materials having these characteristics include polymersgenerally as well as malleable metals generally.

The body 46 can be tailored so that, in an implanted (expanded)configuration, the diameter of the body 46 (i.e., twice the outer radialdimension 68) is suited for implantation in a particular artery. Forexample: Anchor portions 42 tailored for innominate arteries may havediameters in one of the following ranges: 9 to 14 mm inclusive; 10 mm to14 mm inclusive; 11 mm to 13 mm inclusive. Anchor portions 42 tailoredfor subclavian arteries may have diameters in one of the followingranges: 6 to 12 mm inclusive; 7 mm to 11 mm inclusive; 8 mm to 10 mminclusive. Anchor portions 42 tailored for carotid arteries may havediameters in one of the following ranges: 5 mm to 10 mm inclusive; 5 mmto 9 mm inclusive; 6 mm to 8 mm inclusive.

Functionally, the method of implantation of the filter device 20 candepend on the mechanical properties of the materials of which the deviceis composed as well as the shape memory characteristics of the anchorportion 42. For anchor portions 42 that are self-expanding or havingsubstantial shape memory characteristics, the filter device 20 can befolded or rolled to a configuration of reduced diameter adequate forrouting to the implantation site. Once in position at the implantationsite, the anchor portion 42 is released. Because of the substantialelasticity or shape memory, the anchor portion 42 returns substantiallyto the same dimensions. For embodiments where the anchor portion 42 isoversized relative to the effective radius 34 of the artery 26, theanchor portion 42 expands or unfolds to contact the arterial wall 74,creating an interference fit that fixes the filter device 20 in place.In this type of delivery, the filter device initially is situated in acompressed form inside a delivery catheter and liberated duringimplantation by a withdrawal movement of the catheter relative todevice.

For anchor portions 42 having little or no shape memory, the anchorportion 42 can be initially formed as being undersized relative to theeffective radius 34 of the artery 26 at the implantation site. Once inposition, the anchor portion 42 can be expanded, for example by way of aballoon catheter. By initially and momentarily over-expanding the anchorportion 42 to exceed the nominal dimension 34 of the artery 26 with theballoon catheter, the porous wall 48 of the anchor portion 42 is placedin interference with the arterial wall 74, fixing the filter device 20in place. In this type of filter device, the balloon-based deliverysystem passes through the filter device 20, e.g., through one of thepores of the filter cap 44.

For a period of time after implantation, the filter device 20 can bereadily removed from the implantation site using standard minimalinvasive interventional techniques. Accordingly, the filter device 20 issuitable for temporary use. However, over time, tissue ingrowth providesfurther fixation of the cross-members of the porous material or mesh tothe arterial wall 74, further securing the filter device 20 at theimplantation site. Thus, the filer device 20 is suitable for permanentimplantation.

Referring to FIG. 2, an implanted configuration 88 of the filter device20 is depicted in an embodiment of the disclosure. In this embodiment,the filter device 20 is inserted into the ostium 24 of the branch 28 ofthe aortic arch 32 with the proximal end 56 and the filter cap 44extending into the lumen of the aortic arch 32 at an immersion length L1measured parallel to the body axis 66.

Referring to FIG. 2A, an alternative filter device 20 a wherein the body46 includes pore sizes and/or porosity that varies over the length ofthe anchor portion 42 is depicted in an embodiment of the disclosure.That is, the body portion 46 is characterized as having the anchorportion 42 as well as a filter portion 110. In the depicted embodiment,filter device 20 a defines a first porosity 94 having a first averagepore size at the distal end 58 of the body 46, while a second porosity98 having a second average pore size is defined at the proximal end 56of the body 46. In one embodiment, the second porosity 98 can be thesame or nearly the same as the porosity or average pore size of thefilter cap 44, with the first average pore sizes and porosity 94 at thedistal end 58 of the body 46 being substantially greater.

Functionally, the smaller pore sizes and lower porosity at the proximalend 56 provide filtering functionality, while the larger pore sizes andhigher porosity at the distal end 58 can promote tissue ingrowth toprovide better anchoring for permanent implantation. Conversely, thedistal end 58 of the body 46 can be of a tightly woven mesh or of anon-porous construction to inhibit tissue ingrowth, which is moresuitable for temporary implantation.

Referring to FIGS. 3 and 3A, a filter device 90 is depicted in theimplanted configuration 88 and in isolation in an embodiment of thedisclosure. The filter device 90 includes many of the same componentsand aspects as the filter device 20, which are indicated withsame-numbered numerical references in FIGS. 3 and 3A and/or in thefollowing discussion thereof. A difference between the filter devices 20and 20 a and filter device 90 is that, in a standard cylindrical (r-θ-z)coordinate system 91, the porosity of the porous wall 48 varies in atangential dimension θ about the body axis 66. As depicted, and as withthe filter devices 20 and 20 a, the porous wall 48 can comprise themeshed structure 72, but with mesh characteristics that vary in thetangential dimension θ. In one embodiment, an upstream face of the body46 that faces the blood flow defines smaller pores (i.e., lowerporosity) than the surface facing away from the blood flow.

In one embodiment, a first tangential portion 92 of the porous wall 48of the body 46 defines a first porosity 94, and a second tangentialportion 96 of the porous wall 48 defines a second porosity 98 (FIG. 3A),the first tangential portion 92 defining an angle θ1 about the body axis66 and the first porosity 94 being less than the second porosity 98. Invarious embodiments, a non-limiting example of the angle θ1 is in therange of 60° to 270° inclusive. In one embodiment, the angle θ1 is inthe range of 180° to 270° inclusive.

In operation, the filter device 90 can be oriented in a blood flow 99(depicted as streamlines in FIG. 3) so that the first tangential portion92 is upstream of the second tangential portion 96. The blood flow 99 isdepicted as a blood cross flow having a flow vector component that isnormal to the body axis 66. In one embodiment, the first tangentialportion 92 of the porous wall 48 is centered tangentially about thedirection of the blood flow 99 as the blood flow 99 approaches thefilter device 90. In one embodiment, the immersion length L1 issufficiently long so that a portion 99 a of the blood flow 99 thatenters the artery 26 first passes through the porous wall 48 of the body46.

Functionally, the first tangential portion 92 of the filter device 90acts as the primary filter for filtering the blood flow 99 that entersthe artery 26. Debris that does not pass through the first tangentialportion 92 is deflected around the filter device 90 and carried awayfrom the artery. If, over time, the first tangential portion 92 becomesoccluded to the point that not enough blood flow 99 can enter the artery26, blood can still flow into the artery via the second tangentialportion 96; the first tangential portion 92 still functions to deflectdebris away from the ostium 24. The second tangential portion 96 is ofhigher porosity 98 to mitigate against occlusion while still providing asufficient barrier against debris entering the filter device 90.

While varying the porosity of the porous wall 48 in the tangentialdimension θ is depicted for a straight cylinder body in FIGS. 3 and 3A,the general concept of having an upstream face of a filter body possesssmaller pore sizes and/or lower porosity than on a downstream face canbe implemented with any of the embodiments disclosed herein.

Referring to FIG. 4, a filter device 100 is depicted in an embodiment ofthe disclosure and implanted in substantially the same orientation asthe implanted configuration 88 of FIG. 2. The filter device 100 includesmany of the same components and aspects as the filter device 20, whichare indicated with same-numbered numerical references in FIG. 4 and/orin the following discussion thereof. A difference between the filterdevices 20 and 20 a and filter device 100 is that a filter cap 102 ofthe filter device 100 of FIG. 4 presents a convex surface 104 that bowsaway from the proximal end 56 of the body 42 and further into the aorticarch 32 along the body axis 66.

It is noted that, in FIG. 4, the second porosity 98 (smaller mesh) ofthe proximal end 56 extends a ways into the artery 26. That is, theportion of the body 46 that defines the second porosity 98 is actuallygreater than the immersion length L1. The purpose of this arrangement isto better assure that all of the blood entering the artery 26 passesthrough the (finer) second porosity 98, while still providing amplelength of the anchoring portion 42 to provide the desired tissueingrowth. This arrangement can be implement for any of the variousembodiments disclosed herein that include axial variation of theporosity of the body 46.

For the FIGS. 2, 3, and 4 configurations, the proximal end 56 of thebody 46 extends into the lumen of the aortic arch 32. Accordingly, inaddition to the anchor portion 42, the body 46 can include a filterportion 110 configured to function as a filter, i.e., having the samefiltering characteristics as the filter caps 44, 102, effectivelyincreasing filtration area. The filter flow-through area is therebyincreased relative to the implanted configuration 22 of FIG. 1A, whichreduces the risk of filter occlusion with emboli. The extension into thelumen of the aortic arch 32 further enables a higher degree of crossflow across the filter cap 44, 102, enhancing the self-cleaning aspectof the filter device 20, 100. The extension of the body 46 into thelumen of the aortic arch 32 further provides an advantage of protectingthe filter cap 44, 102 from tissue ingrowth. The convex surface 104 ofthe filter cap 102 of FIG. 4 further increases the flow-through area ofthe filter device 100 and further enhances the cross-flow aspect,thereby further enhancing the self-cleaning attribute of the filterdevice.

Referring to FIG. 5, a barbed filter device 120 is depicted in anembodiment of the disclosure. The barbed filter device 120 can includemany of the same aspects and characteristics as the filter device 20, asindicated with same-numbered numerical references in FIG. 5 and/or inthe following discussion thereof. The barbed filter device 120 isequipped with lateral protrusions or barbs 122 or similar structuresthat extend radially beyond the body 46. The lateral protrusions 122 canextend from the filter cap 44 (as depicted) or can extend from the body46 at or near the proximal end 56. In one embodiment, a dimension 124from the body axis 66 to a radial extremity 126 of the protrusions 122is greater than the effective radius 34 of the arterial wall 74.

Functionally, the lateral protrusions 122 interfere with the arterialwall 74 or ostium 24 when implanted. In the embodiment of FIG. 5, theinterference of the protrusions with the ostium 24 effectively registersthe filter cap 44 in the geometrical plane of the ostium 24. In otherembodiments, protrusions 122 are located distal to the filter cap 44(i.e., extend laterally from the body 46) to interfere with the arterialwall 74 when the barbed filter device 120 is pressed into the artery 26.Thus, the barbed filter device 120 is secured by a mechanism other than(or in addition to) interference between the body 46 and the arterialwall 74, and can be positioned precisely in the ostium 24 before beingimplanted using techniques described earlier to provide expansion of theporous wall 48 of the body 46.

Referring to FIGS. 6 and 7, a bulbous filter device 140 is depicted inan embodiment of the disclosure. The bulbous filter device 140 includesmany of the same components and aspects as the above disclosed filterdevices 20 and 100, which are indicated with same-numbered numericalreferences in FIGS. 6 and 7 and/or in the following discussion thereof.In the depicted embodiment, the body 46 defines a flow inlet port 141 atthe proximal end 56, best seen in FIG. 7. The bulbous filter device 140includes a bulbous filter cap 142 that extends from the flow inlet port141 of the proximal end 56 having a convex outer surface 144 that coversthe flow inlet port 141 of the body 46. A hub 146 is positioned on aproximal face 148 of the bulbous filter cap 142. The bulbous filter cap142 further defines an outer lateral dimension 152 (e.g., diameterhaving a radius) normal to the body axis 66. Herein, a characteristic ofa “bulbous” filter element is that the lateral dimension 152 is greaterthan a maximum radial dimension 154 of the body 46. The bulbous filterdevice 140 combines therefore advantages of the barbed filter device 120with the filter devices 20 and 100 by extending into the lumen of aorticarch 32.

In one embodiment, the bulbous filter cap 142 is formed from a flaredportion 156 that extends radially outward from the body axis to definean outer perimeter 158. Without the hub 146, the bulbous filter cap 142defines an open configuration 160, as can be seen in FIG. 7, enablingunfiltered flow through the flow inlet and flow outlet ports 141 and 64of the body 46. In one embodiment, the flared portion 156 is made of anelastic material or a material having shape memory that is formed or setin the open configuration, (for example by a thermosetting process) suchthat, absent the hub 146, the bulbous filter cap 142 will open up and besubstantially restored to the flared configuration 160 of FIG. 7.

Functionally, the bulbous filter cap 142 also provides increasedflow-through area relative to the filter devices 20, 100 and 120,further enhancing the self-cleaning capability of the bulbous filterdevice 140. The hub 146 can be utilized to percutaneously grab andmaneuver the bulbous filter device 140, for example with a purpose builtsnare 162. Also, the hub 146 can be used for removal of the bulbousfilter device 140 from the artery 26. Such removal could be done atoperator discretion several days or weeks after implantation in case ofshort term need for embolic protection. The operator in this case cancatch the hub 146 with the purpose built snare 162 and remove thebulbous filter device 140 from the artery by traction. It is alsocontemplated to implement a hub or similar structure in any of thefilter devices (e.g., 20, 100, 120), whether bulbous or not, tofacilitate removal.

In cases where the bulbous filter device 140 is left for a long periodof time in the ostium 24 of the artery 26 and is affixed thereto byingrown tissue, the removal of the entire device 140 can be impossibleusing minimally invasive surgical techniques. For such long term orpermanent installations, and as a precautionary measure, the hub 146 canbe removed in certain embodiments to open up the bulbous filter cap 142into the open configuration 160 should the bulbous filter cap 142somehow become obstructed. Restoration to the original openconfiguration 160 is provided by the elastic forces or the shape memorymaterial.

Referring to FIGS. 8A through 8F, assembly of bulbous filter device 140is depicted in embodiments of the disclosure. In assembly, and prior toimplantation, the outer perimeter 158 of the flared portion 156 (FIG.8A) is gathered together at a bunched neck 164 (FIG. 8B) that can betied together by the hub 146 to form the bulbous filter cap 142. Variousways to join the outer perimeter 158 at the hub 146 include: screwingthe hub 146 onto the bunched neck 164 (FIG. 8C); crimping the hub 146onto the bunched neck 164 (FIG. 8D); fusing the bunched neck together (afused portion 166 forming the hub 146) (FIG. 8E); stapling the bunchedneck 146 together (a staple 168 serving as the hub 146) (FIG. 8F). Forthese embodiments, removal of the hub 146 to restore unfiltered flow canbe accomplished, for example, by: unscrewing the hub 146; cuttingthrough the bunched neck proximate the hub 146; cutting through orotherwise removing the staple that serves as the hub 146.

Referring to FIG. 9, a bulbous filter device 180 having a detachablebulbous filter cap 182 is depicted in an embodiment of the disclosure.The bulbous filter device 180 is a variation of the bulbous filterdevice 140 of FIGS. 6 and 7, and includes many of the same componentsand aspects, which are indicated with same-numbered numerical referencesin FIG. 9 and/or in the following discussion thereof. In one embodiment,the detachable bulbous filter cap 182 is pre-formed in the bulbousgeometry rather than being gathered in a bunched neck at the hub 146.The detachable bulbous cap 182 can be mounted to a flange 184 thatextends radially outward from the proximal end 56 of the body 46. Inthis embodiment, the hub 146 can be an optional accessory, utilized tograb and maneuver the bulbous filter device with the purpose built snare162 and to remove the detachable bulbous filter cap 182 from the flange184. In some embodiments, the junction between the detachable bulbouscap 182 and the flange 184 can be deliberately weakened relative to theremaining structure of the bulbous filter device 180, so that thedetachable bulbous cap 182 will separate or tear away from the flange184 upon exertion of a sufficient pulling force on the hub 146 in theevent that the detachable bulbous filter cap 182 becomes occluded.

Referring to FIG. 10, a detachable bulbous filter device 180 a isdepicted in an embodiment of the disclosure. The detachable bulbousfilter device 180 a is a variation of the bulbous filter device 180, andas such includes many of the same aspects and components as thedetachable bulbous filter device 180, which are indicated withsame-numbered numerical references in FIG. 10 and/or in the followingdiscussion thereof. The detachable bulbous filter device 180 a includesa stem portion 192 that extends distal to the bulbous filter cap 182.The stem portion 192 has an outer wall 194 dimensioned to fit within theanchor portion 42 (e.g., to have a smaller outer diameter 196 than aninner diameter 198 of the inlet port 141 of the body 46). The stemportion 192 can also comprise a meshed structure. In some embodiments,the stem portion 192 comprises a self-expanding material.

Functionally, the outer diameter 196 of the stem portion 192 contactsthe inner surface 52 of the anchor portion 42. The contact providessufficient interlocking resistance to hold the bulbous filter cap 182within the anchor portion 42, while enabling the detachable bulbousfilter cap 182 to be removed from the anchor portion 42 for replacement.For embodiments implementing the self-expanding material for the stemportion 192, the interlock between the stem portion 192 and the anchorportion 42 can be further enhanced. It is noted, however, that inoperation, blood flow through the assembly (bottom to top in FIG. 10)will tend secure the stem portion 192 within the anchor portion 42;accordingly, the interlock between the stem portion 192 and the anchorportion 42 can be light for easier removal.

While the meshed structure of the stem portion 192, when utilized, mayexperience some ingrowth of tissue over time, the stem portion 192 isseparated from the arterial wall 74 by the body 46 of the anchor portion42, which can substantially reduce the amount of ingrowth, to the pointthat the stem portion 192 can be removed from the anchor portion 42 evenin a permanent installation.

In replacement, the stem portion 192 of the detachable bulbous filtercap 182 can be readily slid into the body 46 of the anchor portion 42.In some embodiments, the stem portion 192 comprises a self-expandingmaterial so that the stem portion 192, initially undersized, grows intoseating contact with the inner surface 52 of the body 46 being insertedin the body 46.

Referring to FIG. 11, another bulbous filter device 200 is depicted inan embodiment of the disclosure. The bulbous filter device 200 is avariation of the bulbous filter device 140 of FIG. 6, and includes manyof the same components and aspects, which are indicated withsame-numbered numerical references in FIG. 11 and/or in the followingdiscussion thereof. In this embodiment, a bulbous filter cap 202 definesa proximal opening 204 on a proximal face thereof. A peripheral portion208 of the bulbous filter cap 202 is adjacent the proximal opening 204.The hub 146 includes a disc portion 212 that is disposed over or withinthe proximal opening 204 of the bulbous filter cap 202, the disc portion212 being in overlapping contact with and being joined to the peripheralportion 208.

In this embodiment, the bulbous filter cap 202 can comprise an elasticor a shape memory material that assumes a flared shape akin to FIG. 7,such that the bulbous geometry of the bulbous filter cap 202 ismaintained by the joinder of the disc portion 212 and the flared portion156 (FIG. 7). In some embodiments, the junction between the bulbousfilter cap 202 and the disc portion 212 of the hub 146 are deliberatelyweakened relative to the remaining structure of the bulbous filterdevice 200, so that the disc portion 212 will separate or tear away fromthe bulbous filter cap 202 upon exertion of a sufficient pulling forceon the hub 146 in the event that the bulbous filter cap 202 becomesoccluded.

In various embodiments, upon removal of the hub 146 and disc portion122, the bulbous filter cap 140 assumes an open configuration akin tothe open configuration 160 of FIG. 7. Joinder of the disc portion 212 tothe bulbous filter cap 202 for the open configuration alternative can beaccomplished in several ways, including but not limited to: adhesivedisposed between the disc portion 212 and the peripheral portion 208 ofthe bulbous filter cap 202; fusion or welding.

The tear away aspect of the bulbous filters 182, 202 can be accomplishedin several ways, including but not limited to: appropriate amounts andselection of adhesive at the junctions; appropriate levels of fusion orwelding, provided, for example, by discrete point tack welding;frangible structure at or adjacent the junctions; and electrolyticerosion. An example of electrolytic erosion is presented, for example,at U.S. Pat. No. 7,862,602 to Licata et al.

Referring to FIG. 12, a sectional view a bulbous filter device 220having a resilient bulbous filter cap 222 and a replaceable disk 226with hub 224 is depicted in an embodiment of the disclosure. The bulbousfilter device 220 includes many of the same aspects and characteristicsas the bulbous filter device 200, as indicated with same-numberednumerical references in FIG. 12 and/or in the following discussionthereof. The bulbous filter device 220 takes on the same generalappearance as the bulbous filter device 200 of FIG. 11. However, unlikethe disc portion 212 of the bulbous filter device 200, the disk 226 doesnot function to maintain the bulbous geometry of the bulbous filter cap222 by joinder to an otherwise flared portion; rather, the bulbousfilter cap 222, is pre-formed to be resilient in the bulbous geometry,so as to maintain the bulbous geometry sans the disc portion 226.

The disc portion 226 includes an outer perimeter 228 that seats on aninner surface 232 of the bulbous filter cap 222. In one embodiment, thedisc portion 226 defines a convex profile 234 that is bowed towards theproximal opening 204. The diameter of the disc portion 226 can bedimensioned to provide a close fit between the outer perimeter 228 andthe inner surface 232, at or near a lateral extremity 236 of the innersurface 232 of the bulbous filter cap 222.

In operation, all blood that flows through proximal opening 204 or theperipheral portion 208 of the bulbous filter cap 222 then flows throughthe filtering structure of the disc portion 226 by virtue of the closefit between the outer perimeter 228 and the inner surface 232 at or nearthe lateral extremity 236. The dynamic response of the disc portion 226to the blood flow therethrough can also slightly flatten the convexprofile 234, causing the outer perimeter 228 to extend slightly radiallyoutward, thereby further enhancing the seating between the disc portion226 and the inner surface 232 of the bulbous filter cap 222. In variousembodiments, the disc portion 226 comprises a self-expanding material,further augmenting the seating between the disc portion 226 and theinner surface 232 due to the elastic expansion force of theself-expanding material.

Referring to FIG. 13, the bulbous filter device 220 is depicted with thereplaceable disk 226 removed from the bulbous filter cap 22 with thepurpose built snare 162. The resilient property of the bulbous filtercap 224 facilitates replacement of the disc portion 226, should the discportion 226 become occluded. To remove the disc portion 226, the hub 224is snared and a pulling force exerted in a direction parallel to thebody axis 66, as depicted in FIG. 13. The pulling force causes the disk226 to contract and/or the proximal opening 204 to expand as the discportion 226 is pulled through the proximal opening 204. The resiliencyof the bulbous filter cap 222 causes the proximal opening 204 to returnsubstantially to the pre-stressed dimension.

In replacement, a new disc portion 226 is folded to a dimension thatclears the proximal opening 204 and fed through the proximal opening 204and left to unfold within the bulbous filter cap 222. The hub 224 can beused for gripping, orienting, and maneuvering the filter disc portion226.

For the various bulbous filter devices 140, 180, 180 a, 200, and 220,the respective bulbous cap 144, 182, 202, and 222 is of larger radialdimension than the body of the anchor portion 42. Accordingly, therespective bulbous filter device can act to register the bulbous filterdevice at the mouth of the ostium 24 (e.g., as presented for bulbousfilter device 140 at FIG. 6). In other embodiments, the body 46protrudes into the aortic arch 32 (e.g., as depicted for bulbous filterdevice 180 at FIG. 9), so that the proximal portion 56 of the body 46acts as a filter, as discussed attendant to FIGS. 2, 3, and 4 above.

Referring to FIGS. 14 through 20, filter devices 250 that include bypassapertures 252 are depicted in implanted configurations 254 inembodiments of the disclosure. The filter devices 250, bypass apertures252, and implanted configurations 254 are herein referred tocollectively or generically by the numerical references 250, 252, and254 respectively, and individually with a letter suffix (e.g., filterdevice 250 a, bypass aperture 252 a, and implanted configuration 254 a).The implanted device depictions of FIGS. 14 through 20 showing flowthrough the aortic arch 32 portray only the outline of the filterdevices 250 (i.e., without depicting meshed walls) for illustrativeclarity; representative and non-limiting porous wall structures areillustrated in the various isolated device depictions related to FIGS.14 through 20.

In one embodiment, as illustrated in FIG. 14, a filter device 250 a caninclude many of the same components and aspects as the filter devices20, 20 a, and 90, which are indicated with same-numbered numericalreferences in FIG. 14 and/or in the following discussion thereof. Adifference between the filter devices 20, 20 a, and 90 and the filterdevice 250 a is that filter device 250 a does not include a filter capat the proximal portion 56; rather, the filter portion 110 at theproximal portion 56 of the body 46 defines an opening 255 that is leftopen to define the bypass aperture 252 a. The filter portion 110 extendsover the immersion length L1 of the filter device 250 a. As disclosedabove, the pores of the anchor portion 42 and the filter portion 110 candefine first and second porosities 94 and 98, respectively, the secondporosity 98 including pores of smaller size and/or defining a lowerporosity than the first porosity 94 of anchor portion 42. In oneembodiment, the first porosity 94 of anchor portion 42 extendscircumferentially around the anchor portion 42, and the second porosity98 of the filter portion 110 extends circumferentially around the filterportion 110. Alternatively, the porosities of the porous wall 48 canvary tangentially as depicted and discussed attendant to filter device90 (FIG. 3), with the coarser first porosity 94 being oriented to facein the downstream direction 97 of the aortic arch 32. In one embodiment,the filter device 250 a is cylindrical, defining an inner diameter D1,and the immersion length L1 into to the aortic arch 32 is at least aslong as the diameter D1.

In implantation and operation, the immersion length L1 for the implantedconfiguration 254 a is of sufficient length so that the portion 99 a ofthe blood flow 99 that enters the artery 26 first passes through theporous wall 48 of the body 46. In the implanted configuration, anupstream portion 258 of the porous wall 48 that faces upstream into theblood flow 99 performs the majority of the filtering. In the event thatthe upstream portion 258 becomes occluded, the blood flow 99 coursesaround the occlusions and enters the filter device 250 a closer to thelateral sides of the filter device 250 a. Because none of thestreamlines of the blood flow 99 enter the bypass aperture 252 a, noneof the blood entering the filter device 250 a is unfiltered. This istrue even when the filter device 250 a becomes partially occluded.

In another embodiment, as illustrated in an implanted configuration 254b in FIG. 15, a filter device 250 b can include many of the samecomponents and aspects as the filter device 100 of FIG. 4, which areindicated with same-numbered numerical references in FIG. 15 and/or inthe following discussion thereof. As disclosed above, the pores of theanchor portion 42 and the filter portion 110 can define first and secondporosities 94 and 98, respectively, the second porosity 98 includingpores of smaller size and/or defining a lower porosity than the firstporosity 94 of anchor portion 42. In one embodiment, the first porosity94 of anchor portion 42 extends circumferentially around the anchorportion 42, and the second porosity 98 of the filter portion 110 extendscircumferentially around the filter portion 110. A difference betweenthe filter device 100 and the filter device 250 b is that filter device250 b includes a bypass aperture 252 b formed on the porous wall 48 nearthe proximal end 56. The bypass aperture 252 b is typically oriented toface away from the blood flow 99, i.e., in a downstream direction 97.

Herein, “lateral” bypass apertures are so named because they face atleast partially in a direction normal to an axis of the anchor portion.In some embodiments (e.g., FIG. 17, discussed infra), the lateralaperture is formed by curving the body 46 so that an open end of thebody is so-oriented. In some embodiments, the lateral aperture is formedon the side of the body 46 (e.g., FIG. 15, discussed infra).

In an embodiment as illustrated in an implanted configuration 254 c inFIG. 16, a filter device 250 c can include many of the same componentsand aspects as the bulbous filter device 140 of FIG. 6, which areindicated with same-numbered numerical references in FIG. 16 and/or inthe following discussion thereof. As disclosed above, the pores of theanchor portion 42 and the bulbous filter cap 142 can define first andsecond porosities 94 and 98, respectively, the second porosity 98including pores of smaller size and/or defining a lower porosity thanthe first porosity 94 of anchor portion 42. In one embodiment, the firstporosity 94 of anchor portion 42 extends circumferentially around theanchor portion 42, and the second porosity 98 of the filter portion 110extends circumferentially around the filter portion 110. A differencebetween the bulbous filter device 140 and the filter device 250 c isthat filter device 250 c includes a lateral bypass aperture 252 c formedon the bulbous filter cap 142 near the proximal end 56. The lateralbypass aperture 252 c is typically oriented to face away from the bloodflow 99.

In the embodiment illustrated in implanted configuration 254 d in FIG.17 (depicted in isolation in FIG. 17A), a filter device 250 d includesmany of the same components and aspects as the filter device 20, whichare indicated with same-numbered numerical references in FIG. 17 and/orin the following discussion thereof. In the depicted embodiment, thefirst porosity 94 of anchor portion 42 extends circumferentially aroundthe anchor portion 42, and the second porosity 98 of the filter portion110 extends circumferentially around the filter portion 110 (FIG. 17A).The body 46 of the filter device 250 d defines a curved cylinder 259about a curved body axis 66. The filter portion 110 of the curvedcylinder 259 of the filter device 250 d includes an elbow portion 260defined near the proximal end 56, the elbow portion 260 defining alateral bypass aperture 252 d. In the depicted embodiment, the bypassaperture 252 d intersects the body axis 66 at a substantially rightangle. In one embodiment, the curved cylinder 259 includes an extensionportion 262 that extends in the radial direction r of the cylindricalcoordinate system 91. The bypass aperture 252 d is typically oriented toface away from the blood flow 99.

A characteristic of the filter device 250 d, and of embodimentsgenerally that define a curved body axis 66, the flow outlet port 64 isnormal to a first axis 253, and the lateral bypass aperture 252 d isnormal to a second axis 257, the axes 253 and 257 being concentric withthe curved body axis 66. The first axis 253 is not parallel to thesecond axis 257; that is, the second axis defines a non-zero angle withrespect to the first axis. The depiction of FIG. 17A presents the firstand second axes 253 and 257 as being substantially normal to each other.For various embodiments, the filter device 250 d defines an angle thatis in a range of 60° to 120° inclusive; in some embodiments, in a rangeof 70° to 110° inclusive; in some embodiments, in a range of 80° to 100°inclusive.

In the embodiment illustrated in implanted configuration 254 e in FIG.18, a filter device 250 e can include many of the same components andaspects as the filter device 20, which are indicated with same-numberednumerical references in FIG. 18 and/or in the following discussionthereof. The filter portion 110 of the filter device 250 e defines acurved cylinder 259 that, at least in the implanted configuration,includes or expands into an arcuate or elbow-shaped portion 260 definednear the proximal end 56, with the body axis 66 being curved through theelbow-shaped portion 260. As disclosed above, the pores of the anchorportion 42 and the filter portion 110 can define first and secondporosities 94 and 98, respectively, the second porosity 98 includingpores of smaller size (finer porosity or mesh) and/or defining a lowerporosity than the first porosity 94 of anchor portion 42. Theelbow-shaped portion 260 defines a bypass aperture 252 e. In thedepicted embodiment, the bypass aperture 252 e lies substantially on aplane 262 that intersects the curved body axis 66 at an acute angle ϕ.The bypass aperture 252 e is typically oriented to face away from theblood flow 99. By this arrangement, coverage of both the ostia of afirst artery 272 and an adjacent artery 274 is provided.

For the embodiment illustrated in implanted configuration 254 f in FIG.19, filter device 250 f includes many of the same components and aspectsas the filter device 250 d of FIGS. 17 and 17A, which are indicated withsame-numbered numerical references in FIG. 19 and/or in the followingdiscussion thereof. Like the filter device 250 d, device 250 f definesthe curved cylinder 259 and the filter portion 110 includes theelbow-shaped portion 260 near the proximal end 56, and a bypass aperture252 f that intersects the body axis 66 at a substantially right angle.The bypass aperture 252 f is typically oriented to face away from theblood flow 99.

For the filter device 250 f, an elongated extension portion 262 f of thefilter portion 110 has sufficient lateral dimension L to extendlaterally (i.e., in the radial direction r of the r-θ-z coordinate 91)from the elbow-shaped portion 260 over the ostium of an adjacent artery274 (e.g., the ostium of the left carotid artery and, in someembodiments, also the left subclavian artery of FIG. 1) when the filterdevice 250 f is implanted in a first artery 272 (e.g., the innominateartery of FIG. 1). In one embodiment, the elongated extension portion262 f is dimensioned to have a larger diameter than the anchor portion42 to augment full coverage of the ostium of the adjacent artery,thereby compensating for directional alignment uncertainty. In someembodiments, the elongated extension portion 262 f can be resilient andpre-formed to define an elliptical cross-section (not depicted) with themajor axis of the ellipse being oversized to augment full coverage ofthe ostium of the adjacent artery. In some embodiments, the extensionportion 262 f can be resilient and define a circular cross-section, but,under the stresses imposed on the elongated extension portion 262 f inthe implanted configuration 254 f, assumes an elliptical cross-section.

Referring to FIGS. 19A and 19B, the filter device 250 f is depicted inembodiments of the disclosure. The depicted embodiments of FIGS. 19A and19B are the same, except the FIG. 19B embodiment includes a centeringhook 276. In these embodiments, the porosities of the porous wall 48 areconfigured to vary tangentially, akin to filter device 90 depicted anddiscussed attendant to FIG. 3. The filter device 250 f is configured sothat a superior face 282 and a downstream-oriented face 284 of the body46 defines the (coarser) first porosity 94, the downstream-oriented face284 being axially adjacent to the superior face 282 along the curvedbody axis 66. The filter device 250 f is further configured so that aninferior face 286 and an upstream-oriented face 288 of the body 46includes the (finer) second porosity 98, the upstream-oriented face 288being axially adjacent to the inferior face 286 along the curved bodyaxis 66.

Functionally, having the finer second porosity 98 on the inferior andupstream-oriented faces 286 and 288 provides filtration of the bloodflow 99 a entering the implanted first artery 272 (e.g., the innominateartery), as well as a blood flow 99 b entering the adjacent artery 274(e.g., the left carotid artery). The coarser first porosity 94 on thesuperior and downstream-oriented faces 282 and 284 enhances tissueingrowth into the filter device 250 f over time for better anchoring.Also, having the coarser first porosity 94 cover ostium of the adjacentartery 274 partially mitigates the double filtering of the enteringblood stream and attendant restriction in blood flow.

By orienting the bypass apertures 252 b-252 f to face away from theblood flow 99, an outflux 270 of blood through the bypass apertures 252b-252 f is maintained under normal operating conditions. That is, bloodflow 99 that enters the filter devices 250 b-250 f (i.e., through theporous wall 48, the bulbous filter cap 142, or the elbow-shaped portion260) that is not drawn into the artery 26 will pass through the bypassapertures 252 b-252 f of filter devices 250 b-250 f. Accordingly, anydebris that is deflected by the filter devices 250 b-250 f will bypassthe bypass apertures 252 b-252 f and not be drawn into the filterdevices 250 b-250 f. The outflux 270 can be maintained (albeit at lessintensity) even if the filter device 250 b-250 f becomes partiallyoccluded. Thus, despite the presence of unfiltered bypass apertures 252,blood flow 99 a entering the artery 26, blood flow 99 a entering theartery 26 still passes through a filter medium in normal operation, andeven when the filter device 250 is in a partially occluded state.

In the unlikely event that the filter device 250 b-250 f becomes soheavily occluded as to interrupt normal operation, blood can still flowinto resident artery. In such a scenario, some of the blood flowing pastthe heavily occluded filter portion 110 would be drawn into the bypassapertures 252 b-252 f to enter the artery.

In various embodiments, the bypass apertures 252 are sized to defineaccess ports dimensioned to permit surgical instruments to pass throughthe filter device 250 for servicing of the artery 26, without need fordestroying or otherwise compromising the filter device 250. The bypassapertures 252 can also allow transradial access to thoracic aorta whenthe filter device is implanted, for example, in the ostium of innominateartery or left subclavian artery. The bypass aperture 252 can alsopermit blood flow therethrough in the unlikely event that the filterdevice 250 becomes heavily occluded.

For the embodiment illustrated in implanted configuration 254 g in FIG.20, filter device 250 g includes many of the same components and aspectsas the filter device 250 f of FIGS. 19, 19A, and 19B, which areindicated with same-numbered numerical references in FIG. 20 and/or inthe following discussion thereof. Like the filter device 250 f, device250 g defines the curved cylinder 259, and the filter portion 110includes the elbow-shaped portion 260 near the proximal end 56, with anelongated extension portion 262 g of the filter portion 110 havingsufficient lateral dimension L to extend laterally from the elbow-shapedportion 260 over the ostium of the adjacent artery 274 when the filterdevice 250 g is implanted in a first artery 272.

The filter device 250 g defines a slot 271 that extends along theelongated extension portion 262 g and faces in the superior direction30. As such, in the depicted embodiment, a downstream or lateral end 273of the elongated extension portion 262 g does not define a tube andaperture, but rather a channel 275 and channel opening 277. The channelopening 277 is typically oriented to face away from the blood flow 99.Depending on the length of the slot 271, the filter device 250 g canalso incorporate the optional centering hook 276 of the filtering device250 f.

In the implanted configuration 254 g, the channel 275 passes over theostium of the adjacent artery 274. In one embodiment, the channel 275contacts the wall of the aortic arch 32, and the slot 271 and channel275 provide an opening on the elongated extension portion 262 g thataligns over the ostium of the adjacent artery 274. Also, akin to theelongated extension portion 262 f, the elongated extension portion 262 gcan be resilient and pre-formed to outline a generally ellipticalcross-section, or can assume the elliptical cross-section under thestresses of the implanted configuration 254 g.

Functionally, for filter devices 250 f and 250 g, the dimensioning theelongated extension portion 262, 262 g to cover the ostium of theadjacent artery 274 provides an additional degree of filtration andprotection of the adjacent artery 274. In some embodiments, the lateraldimension L is long enough to cover more than one adjacent artery 274.For example, the lateral dimension L can be sized so that the filterdevice 250 f, 250 g, when mounted in the innominate artery, extends tocover both the left carotid artery and the left subclavian artery ofFIG. 1. Blood can still flow through the porous walls of the elongatedextension portion 262 to enter the adjacent artery 274, while embolithat could otherwise swirl into the adjacent artery 274 would begenerally blocked by the porous walls of the elongated extension portion262, 262 g. Furthermore, the slot 271 and channel 275 of the filterdevice 250 g entirely eliminates any double filtering of the blood flow99 b entering the adjacent artery 274. “Double filtering” occurs when ablood flow must pass through the filter portion 110 twice, which imposesan unnecessary and generally undesirable restriction to blood flow. Theslot 271 eliminates the porous wall 48 that would otherwise beimmediately adjacent the ostium of the adjacent artery 274, so there isno double filtering of the blood flow 99 b.

As discussed attendant to FIGS. 20A and 20B below, the slot 271 andchannel 275 of filter device 250 g further enable the elongatedextension portion 262 g to spread or flare out at the channel opening277, effectively enlarging the width of the elongated extension portion262 g to augment full coverage of the ostium of the adjacent artery 274,thereby compensating for directional alignment uncertainty.

Referring to FIGS. 20A and 20B, filter devices 250 h and 250 i aredepicted, respectively, in embodiments of the disclosure. The filterdevices 250 h, 250 i are embodiments of the filter device 250 g, and assuch include all of the components and aspects as the filter device 250g, which are indicated with same-numbered numerical references in FIGS.20A and 20B and/or in the following discussion thereof. Also, the filterdevices 250 h, 250 i can include some components and attributesidentified for the filter device 250 f of FIGS. 19, 19A, and 19B, whichare also identified with same-numbered numerical references in FIGS. 20Aand 20B and/or in the following discussion thereof.

For filter device 250 h, the slot 271 extends over a portion of theelongated extension portion 262 g. For the filter device 250 i, the slot271 extends over the entire length of the elongated extension portion262 g, through the elbow-shaped portion 260, and into the anchor portion42 of the body 46. Generally, for a given stiffness of the porous wall48, the longer the slot 271, the wider the elongated extension portion262 g can be spread or fanned out at the channel opening 277, such thatthe filter portion 110 defines a fanned filter portion 110 g. The fannedfilter portion 110 g is depicted in dashed lines in FIGS. 20A and 20B.In relative terms, the shorter slot of FIG. 20A provides a channelopening 277 having less fanning (narrower spread) with a larger openingdimension in the superior direction 30; the longer slot of FIG. 20Bprovides a channel opening with greater fanning (wider spread) with asmaller opening dimension in the superior direction 30.

Accordingly, for a given stiffness of the porous wall 48, the channelopening 277 can be tailored to a desired depth in the implantedconfiguration 254 g by dimensioning of the slot 271. In one embodiment,the fanning of the filter portion 110 can eliminate or nearly eliminateany definition of an open channel 277, such as depicted in FIG. 20B. Insuch an embodiment, the fanned filter portion 110 g is akin to a flapthat effectively lays over the ostium of the adjacent artery 274. Forthese embodiments, the porous wall 48 can be configured with sufficientflexibility to enable the fanned filter portion 110 g to be lifted awayfor access to both the adjacent artery 274 and the first artery 272.

In various embodiments, the fanned filter portion 110 g defines amaximum width dimension that is in a range of 6 mm to 20 mm inclusive;in some embodiments, a range of 6 mm to 15 mm inclusive; in someembodiments, a range of 7 mm to 12 mm inclusive; in some embodiments, arange of 7 mm to 10 mm inclusive.

As with the filter device 250 f, discussed attendant to FIG. 19A, theporosities of the porous wall 48 of the filter devices 250 h and 250 ican be configured to vary tangentially. Alternatively, the porosities ofthe porous wall 48 can be configured to vary axially along the curvedbody axis 66, such as with filtering device 250 d of FIG. 17A with thefirst porosity 94 of anchor portion 42 extends circumferentially aroundthe anchor portion 42, and the second porosity 98 of the filter portion110 extends circumferentially around the filter portion 110.

Referring to FIG. 18A and again to FIG. 18, the filter device 250 e ispresented with an optional centering hook 276 in an embodiment of thedisclosure. The FIG. 18 depiction (as well as the FIGS. 19 and 20depictions) presents the first artery 272 as an innominate artery, andalso presents the adjacent artery 274 as the left carotid arteryextending from the aortic arch 32. The filter device 250 e canoptionally include the centering hook 276 extending laterally outward(i.e., in a direction away from the curved body axis 66) from the outersurface 54 of the porous wall 48 of the filter device 250 e (FIG. 18A).

The centering hook 276 can be dimensioned to bridge the ostia of thefirst artery 272 and the adjacent artery 274, and to extend into thefirst artery 272 and the adjacent artery 274, as depicted in FIG. 18. Invarious embodiments, the centering hook 276 is fabricated from aresilient material so that it is held in place in part by restorativeelastic forces incurred during implantation. That is, the centering hook276 can be dimensioned to define a span 279 that is undersized (FIG.18A), so that inserting the centering hook 276 in place between theadjacent ostia of the arteries 272 and 274 causes the span 279 to expandafter insertion. The span 279 is defined as the distance between a freeend 281 and a shank portion 283 of the centering hook 276 in a directionperpendicular to the portion of the body axis 66 that passes through theanchor portion 42 of the filter device 250 e. The expansion of the span279 generates a restorative force that holds or pinches the filterdevice 250 e between the centering hook 276 and the ostium. Optionally,or in addition, the centering hook 276 can be attached to the porouswall 48 by various means available to the artisan, including fusion tothe porous wall 48, or by integral formation with the wall 48. In oneembodiment, the centering hook 276 can be integrally formed as anextension of one of the cross-members of a meshed structure (e.g., oneof the cross-members 82 of meshed structure 86 of FIG. 1D).

The centering hook 276 can also include a spherical or otherwiseradiused barb 278. The radiused barb 276 presents dulled (i.e., notsharp) features, as opposed to traditional barbs that are designed totenaciously set into a target. In comparison to traditional barbs, theradiused barb 278 is less prone to tearing the tissue both during theapproach and at target. The radiused barb 278 is also less prone totearing the filter device 250 d during approach and implantation.

Functionally, the centering hook 276 can help maintain the angularorientation (θ orientation of the cylindrical coordinate system 91) ofthe filter device 250 e, which further aids in aligning and maintainingalignment of the bypass aperture 252 e in an orientation that faces awayfrom the blood flow 99. The radiused barb 278 can also promote thepermanency of the installation, as tissue grows over the radiused barb278 over time; because the radiused barb is not sharp, such tissuegrowth can occur without the radiused barb 278 cutting through thegrowth tissue.

In some embodiments, the centering hook 276 further induces thecurvature of the elbow-shaped portion 260 when the filter device 250 eis in the implanted configuration 254 e. That is, prior to implantation,the filter device 250 e may assume a straight configuration, or at leasta straighter (less arcuate or less pronounced elbow shape) configurationthan in the implanted configuration 254 e. The centering hook 276 can bejoined to the filter device 250 e such that, when hooked to the ostiumof the adjacent artery 274, the elbow-shaped portion 260 becomes fullydefined. In this manner, the filter device 250 d can provide a lowerprofile during the approach. Alternatively, or in addition, the elbowportion 260 can be permanently formed by, for example, a thermosettingprocess or by use of a shape-memory materials.

Referring to FIG. 21, a detached centering hook 280 is depicted in anembodiment of the disclosure. The detached centering hook 280 is notconnected to the filter device 250 e; instead the centering hook 280 isinstalled separately as a clip. In one embodiment, the centering hook280 includes the radiused barbs 278 on both the free end 281 and anopposed free end 285. In this embodiment, the span 279 is taken as thedistance between the free end 281 and the opposed free end 285. The FIG.21 depiction also represents both the span 279 and an expanded span 279a in phantom that generates the restorative force that holds or pinchesthe wall 48 of the filter device 250 e between the centering hook 280and the ostium. In various embodiments, the detached centering hook 280can be utilized as a retrofit to previously implanted filter devices250. The detached centering hook 280 provides the same retention andalignment functionality as the centering hook 276, discussed above.

While the centering hooks 276, 280 are described in association with thefilter devices 250 e, it is understood that centering hooks 276, 280 canbe implemented with a variety of the filter devices 250 of the presentdisclosure. For example, the centering hook 276 (or optionally detachedcentering hook 280) can be implemented with the filter device 250 f toaid in aligning and maintaining alignment of the elongated extensionportions 262 f, 262 g to cover the ostium of the adjacent artery 274.The centering hook 276, 280 further aids in maintaining the bypassaperture 252 f or channel opening 277 oriented in the downstreamdirection 97.

Referring to FIGS. 22, 22A, and 22B, a dual anchor filter device 300 ais depicted in an embodiment of the disclosure. A variety of dual anchorfilter devices 300 are disclosed herein, referred to collectively orgenerically by the numerical reference 300 and individually with aletter suffix (e.g., filter device 300 a). The dual anchor filter device300 a includes a first anchor portion 302 and a second anchor portion304 disposed on opposing ends of a filter portion 306. The first anchorportion 302 defines a first outer diameter 308 and includes many of thesame components and aspects as, for example, the filter devices 20,which are indicated with same-numbered numerical references in FIGS. 22,22A, and 22B and/or in the following discussion thereof. The secondanchor portion 304 is of similar construction to the first anchorportion 302, defining a second outer diameter 312, a second flow outletport 314, and including a porous wall 316 that defines a porosity 318.In one embodiment, the porosity 318 is substantially the same as thefirst porosity 94 of the first anchor portion 302.

In some embodiments, the first anchor portion 302 is dimensioned foranchoring to the first artery 272 and the second anchor portion 304 isdimensioned for anchoring to the adjacent artery 274. It is noted that,while the adjacent artery 274 may be generally of a different diameterthan the first artery 272, the first and second outer diameters 308 and312 can be of the same dimension and still function to reliably anchorthe respective anchor portions 302 and 304.

Referring to FIG. 23, a dual anchor filter device 300 b is depicted inan embodiment of the disclosure. The dual anchor filter device 300 bincludes many of the same components and aspects as the dual anchorfilter device 300 a, which are indicated with same-numbered numericalreferences in FIG. 23 and/or in the following discussion thereof. Thedual anchor filter device 300 b is characterized as having first andsecond diameters 308 and 312 that are of different dimension, with thesecond diameter 312 being less than the first diameter 308.

In the depicted embodiment, a transition 320 between the first andsecond diameters 308 and 312 is defined on a part of the porous wall 48having the second porosity 98. This enables the (finer) second porosityto extend partially into the ostium of the resident artery 274 forbetter assurance of filtering all of the blood that enters the artery274.

In this embodiment, the first and second diameters 308 and 312 can beconfigured for a more tailored anchoring fit of the first artery 272 andthe adjacent artery 274, respectively. Ranges of representativediameters for various arteries is discussed above attendant to FIGS. 1Athrough 1D. Accordingly, for various embodiments of the dual anchorfilter devices 300 tailored for anchoring in the innominate and the leftcarotid arteries may define a ratio of the first diameter 308 to thesecond diameter 312 in one of the following non-limiting ranges: 1 to 3inclusive; 1.4 to 2 inclusive; 1.6 to 1.8 inclusive. A dual anchorfilter device for anchoring in the left carotid and left subclavianarteries may define a ratio of the first diameter 308 to the seconddiameter 312 in one of the following non-limiting ranges: 0.3 to 1inclusive; 0.5 to 1; 0.9 to 0.7 inclusive. Note that the former rangeclusters have ratios greater than or equal to unity while the latterrange clusters have ratios less than or equal to unity, reflecting thediameters of upstream and downstream arteries for the twoconfigurations.

Referring to FIGS. 24 and 24A, a dual anchor filter device 300 c isdepicted in an embodiment of the disclosure. The dual anchor filterdevice 300 c includes the same components and aspects as the dual anchorfilter device 300 a, which are indicated with same-numbered numericalreferences in FIGS. 24 and 24A and/or in the following discussionthereof. In addition, the dual anchor filter device 300 c includes alateral bypass aperture 322 formed in the filter portion 306. In oneembodiment, the lateral bypass aperture 322 is disposed proximate thesecond anchor portion 304 and oriented to face in the downstreamdirection 97 within the aortic arch 32.

Referring to FIGS. 25 and 25A, a dual anchor filter device 300 d isdepicted in an embodiment of the disclosure. The dual anchor filterdevice 300 d includes the same components and aspects as the dual anchorfilter device 300 c, which are indicated with same-numbered numericalreferences FIGS. 25 and 25A and/or in the following discussion thereof.In addition, the filter portion 302 of the dual anchor filter device 300d includes a shroud 324 formed on the filter portion 306 and protrudingradially outward (i.e., in a direction away from the body axis 66), theshroud 324 surrounding the lateral bypass aperture 322.

Functionally, the dual anchor filter devices 300 provide full filteringof the two arteries 272 and 274 (e.g., the innominate artery and theleft carotid artery). The dual anchors also fix the orientation of thefilter devices 300. The higher porosities 94, 318 (e.g., larger poresizes) of the anchoring portions 302, 304 facilitate tissue ingrowthinto the anchor portions 302 and 304, while the lower porosity 98 (e.g.,small pore sizes) of the filter portion 306 facilitate thoroughfiltering of the blood entering both arteries. The bypass aperture 322,being oriented to face away from the blood flow, operates akin to thebypass apertures 252 described attendant to FIGS. 16 through 20. Theshroud 324 offers an added level of prevention against recirculatingemboli entering the filter.

Referring to FIG. 26, a double filter arrangement 350 is depicted in anembodiment of the disclosure. The double filter arrangement 350 includestwo filter devices, a first or upstream filter device 352 a, and asecond or downstream filter device 352 b. The filter device 352 a isconfigured for implantation in an upstream artery 354 a, and the filterdevice 352 b is configured for implantation in a downstream artery 354b. For the depicted embodiment of the double filter arrangement 350,each of the filter devices 352 a and 352 b include the same componentsand attributes as the filter device 250 d (FIG. 17), which are indicatedwith same-numbered numerical references FIG. 26 and/or in the followingdiscussion thereof. Also for the depicted embodiment, the upstream anddownstream arteries 354 a and 354 b are the innominate and left carotidarteries of FIG. 1.

For certain embodiments that utilize the filter device 250 d in theupstream artery 354 a, a length 356 a of the extension portion 262 isdimensioned to provide a minimum radial separation 358 between thebypass aperture 252 d of the upstream filter device 352 a and the elbowportion 260 of the downstream filter device 352 b. Herein, a “radialseparation” is a dimension parallel the radial direction r of thecylindrical coordinate system 91 of the upstream filter device 352 a.

In various embodiments, non-limiting dimensions for the minimum radialseparation 358 are in the range of 2 mm to 5 mm inclusive. In variousembodiments, to obtain the desired minimum radial separation 358, thebypass aperture 252 d of the upstream filter device 352 a is centered ata lateral dimension L2 in a range of 3 mm to 12 mm inclusive from acenterline of the anchor portion; in some embodiments, a range of 5 mmto 10 mm inclusive; in some embodiments, a range of 5 mm to 8 mminclusive; in some embodiments, a range of 6 mm to 8 mm inclusive.

The configuration of the porous wall 48 of the body 46 of each of thefilter devices 352 a and 352 b may be congruent with various embodimentsdisclosed herein. For the depicted embodiment of the double filterarrangement 350, each of the filter devices 352 a and 352 b include thefirst porosity 94 of anchor portion 42 extending circumferentiallyaround the anchor portion 42, and the second porosity 98 of the filterportion 110 extending circumferentially around the filter portion 110.Alternatively, the anchor and filter portions 42 and 110 of the filterdevices 352 a and 352 b can be configured with porosities 94, 98 thatvary tangentially about the curved body axis 66, akin to the filterdevice 250 f discussed attendant to FIG. 19A. Also, for arrangementssuch as depicted in FIG. 26, where the upstream artery 354 a isproximate the downstream artery 354 b, the upstream filter device 352 amay be configured with a centering hook (not depicted) that bridges theostia of the upstream and downstream arteries 354 a and 354 b, akin tothe centering hook 276 discussed attendant to FIG. 18 or the detachedcentering hook 280 discussed attendant to FIG. 21.

As described above attendant to FIGS. 14 through 20, the bypassapertures 252 d of the upstream and downstream filter devices 352 a and352 b can be sized to define access ports dimensioned to permit surgicalinstruments to pass through the respective filter device 352 a, 352 b,for servicing of the respective artery 354 a, 354 b and without need fordestroying or otherwise compromising the filter device 352 a, 352 b.

Functionally, the downstream-facing orientation of bypass apertures 252d enable transradial access to the arteries 354 a and 354 b. The minimumradial separation 358 enable surgical instrument access to the bypassaperture 252 d of the upstream filter device 352 a without substantiallydisturbing the downstream filter device 352 b. That is, surgicalinstruments (e.g., a guide wire) utilizing a transradial approach canpass over the arcuate surface of the elbow portion 260 of the downstreamfilter device 352 b for entry into the bypass aperture 252 d of theupstream filter device 352 a with little or mere incidental contact withthe downstream filter device 352 b.

Further functional aspects of the double filter arrangement 350 are asprovided in similar embodiments described above. For example, the doublefilter arrangement 350 provides affirmative filtering of both arteries354 a and 354 b (e.g., the innominate artery and the left carotidartery). The higher porosities 94 (e.g., larger pore sizes) of theanchoring portions 42 facilitate tissue ingrowth into the anchorportions 42, while the lower porosities 98 (e.g., small pore sizes) ofthe filter portion 110 facilitate thorough filtering of the bloodentering the respective arteries 354 a and 354 b. The bypass apertures252 d, being oriented to face away from the blood flow, operate akin tothe bypass apertures 252 described attendant to FIGS. 15 through 20. Thebypass apertures 252 d can also permit blood flow therethrough in theunlikely event that the respective filter device 352 a, 352 b becomesheavily occluded.

Alternative embodiments for double filter arrangements 350 a through 350d are presented in FIGS. 26A through 26D in embodiments of thedisclosure. For double filter arrangement 350 a, the upstream filterdevice 352 a does not include an extension portion that extendslaterally from the elbow portion 260; rather, the bypass aperture 252 dis defined on the elbow portion 260 (FIG. 26A). This effectivelyincreases the minimum radial separation 358 relative to the doublefilter arrangement 350, thereby increasing accessibility of the upstreamfilter device 352 a.

For the double filter arrangement 350 b, the upstream filter device 352a is the filter device 250 b, described attendant to FIG. 15 above. Thebypass aperture 252 b of filter device 250 b is defined in on a lateralside of the body 46 (FIG. 26B), such that the lateral dimension L2 islimited to the radius of the filter portion 110. This also increases theminimum radial separation 358 relative to the double filter arrangement350.

For the double filter arrangement 350 c, the upstream filter device 352a is the filter device 250 a, described attendant to FIG. 14 above. Thebypass aperture 252 a is oriented to face primarily in the inferiordirection 31 and at the immersion depth L1 (FIG. 26C). As such, accessto the upstream filter device 352 a is unaffected by the presence of thedownstream filter device 252 b.

For the double filter arrangement 350 d, the upstream filter device 352a is similar to the filter device 250 d of FIGS. 17 and 26, except thatthe filter portion 110 includes an axial extension 368 that extends anaxial length 366 from the ostium of the first artery 354 a (FIG. 26D).The axial extension 368 extends the bypass aperture 252 d in theinferior direction 31 relative to the bypass aperture 252 d of thedownstream filter device 352 b. By this arrangement, access to theupstream filter device 252 a is unfettered by the downstream filterdevice 252 b.

For the depictions of FIGS. 26 and 26A-26D, the downstream filter device352 b is depicted and identified as filter device 250 d. It isunderstood that the double filter arrangements 350, 350 a-350 d are notlimited to the use of filter device 250 d in the downstream artery 354b. Rather, the artisan will recognize that any of the filter devicesutilized in the upstream artery 354 a can also be utilized in thedownstream artery 354 b, as well as several of the other filter devicesdisclosed herein.

The context of the double filter arrangement 350 of the descriptionabove is for implantation in an innominate and a left carotid artery(FIG. 1). It is understood that the principles of the double filterarrangement 350 are not limited to these arteries, or to the use of onlytwo filter devices. That is, in various embodiments, the principlesdescribed can be implemented with any of a variety of take-off arteriesand in some cases with more than two arteries, as recognized by theskilled artisan.

While the embodiments depicted in FIGS. 2 through 26D include some formof variation of the porosity of the body 46, it is contemplated that anyof the embodiments disclosed herein can be optionally configured with asubstantially uniform porosity, such as depicted in FIGS. 1A through 1D.

Each of the additional figures and methods disclosed herein can be usedseparately, or in conjunction with other features and methods, toprovide improved devices and methods for making and using the same.Therefore, combinations of features and methods disclosed herein may notbe necessary to practice the disclosure in its broadest sense and areinstead disclosed merely to particularly describe representative andpreferred embodiments.

Various modifications to the embodiments may be apparent to one of skillin the art upon reading this disclosure. For example, persons ofordinary skill in the relevant art will recognize that the variousfeatures described for the different embodiments can be suitablycombined, un-combined, and re-combined with other features, alone, or indifferent combinations. Likewise, the various features described aboveshould all be regarded as example embodiments, rather than limitationsto the scope or spirit of the disclosure.

Persons of ordinary skill in the relevant arts will recognize thatvarious embodiments can comprise fewer features than illustrated in anyindividual embodiment described above. The embodiments described hereinare not meant to be an exhaustive presentation of the ways in which thevarious features may be combined. Accordingly, the embodiments are notmutually exclusive combinations of features; rather, the claims cancomprise a combination of different individual features selected fromdifferent individual embodiments, as understood by persons of ordinaryskill in the art.

The following references, referred to herein above, are herebyincorporated by reference herein in their entirety except for patentclaims and express definitions contained therein above: U.S. Pat. Nos.6,712,834 and 6,866,680 to Yassour, et al.; U.S. Pat. No. 7,670,356 toMazzocchi et al.; U.S. Pat. No. 6,258,120 to McKenzie et al.; U.S. Pat.No. 8,430,804 to Belson; U.S. Pat. No. 8,062,324 to Shimon et al.; U.S.Pat. No. 8,460,335 to Carpenter; U.S. Pat. No. 7,862,602 to Licata etal.; and U.S. Patent Application Publication No. 2009/0254172 to Grewe.

Any incorporation by reference of documents above is limited such thatno subject matter is incorporated that is contrary to the explicitdisclosure herein. Any incorporation by reference of documents above isfurther limited such that no claims included in the documents areincorporated by reference herein. Any incorporation by reference ofdocuments above is yet further limited such that any definitionsprovided in the documents are not incorporated by reference hereinunless expressly included herein.

References to “embodiment(s)”, “disclosure”, “present disclosure”,“embodiment(s) of the disclosure”, “disclosed embodiment(s)”, and thelike contained herein refer to the specification (text, including theclaims, and figures) of this patent application that are not admittedprior art.

For purposes of interpreting the claims, it is expressly intended thatthe provisions of 35 U.S.C. 112(f) are not to be invoked unless thespecific terms “means for” or “step for” are recited in the respectiveclaim.

What is claimed is:
 1. A blood filter (250 f) for filtering bloodentering an artery (272) from the aorta, comprising: a body (46)defining a curved cylinder (259) about a curved body axis (66),including: an anchor portion (42) defining a flow outlet port (64) at afirst end (58) of said body (46), said anchor portion (42) being adaptedto route the blood flow (99) through said flow outlet port (64) in afirst direction (36), wherein said anchor portion (42) is adapted to beinserted into the ostium of the artery (272); and a filter portion (110)that extends from said anchor portion (42) and includes an elbow-shapedportion (260) that extends lateral to said anchor portion (42) and anextension portion (262 f) that extends from said elbow-shaped portion(260), wherein said filter portion is adapted to protrude into the lumenof the aorta, said anchor and filter portions (42, 110) including porouswalls (48) that define a first porosity (94) and a second porosity (98),said second porosity (98) defining a second average pore size, saidsecond average pore size being less than said first average pore size,said porous wall (48) of said filter portion (110) being adapted toreceive said flow (99) from a second direction that is substantiallynormal to said first direction (36), said extension portion (262 f)defining a second end of said body, said second end defining a bypassaperture (252 f) that is adapted to face in a downstream direction (97)of the blood-flow (99) in the aorta, wherein a superior face (282) ofsaid extension portion (262 f) is adjacent to a downstream-orientedsurface (284) along the curved body axis (66), said superior face (282)and said downstream-oriented face (284) define said first porosity (94),an upstream-oriented face (288) opposite said downstream-orientedsurface (284) of said anchor portion (42) is axially adjacent to aninferior face (286) opposite said superior face (282) of said filterportion (110), and said inferior face (286) and said upstream-orientedface (288) define said second porosity (98).
 2. The blood filter ofclaim 1, wherein said body (46) comprises one of a bio-absorbable alloyand a bio-absorbable polymer.
 3. The blood filter of claim 1, whereinsaid body (46) comprises a material selected from the group consistingof stainless steel, platinum, platinum-iridium alloys, nickel-cobaltalloys, nickel-cobalt-chromium alloys, nickel-titanium alloys, magnesiumbased alloys, polyethylene terephthalate, polyurethane, and polylacticacid based polymers.
 4. The blood filter of claim 1, wherein said body(46) comprises a nickel-titanium alloy.
 5. The blood filter of claim 1,wherein said anchor portion (42) and said filter portion (110) comprisesa shape memory alloy.
 6. The blood filter of claim 1, wherein saidporous wall (48) of said anchor portion (42) defines a porosity in therange of 80% to 95% inclusive.
 7. The blood filter of any one of claim1, wherein said porous wall (48) of said body (48) is a meshedstructure.
 8. The blood filter of claim 1, wherein said first averagepore size is in a range of 800 μm to 5000 μm inclusive and said secondaverage pore size is in a range of 300 μm to 1000 μm inclusive.
 9. Theblood filter of claim 7, wherein said meshed structure of said filterportion (110) defines a nominal open fraction of between 50% and 95%.10. The blood filter of claim 1, wherein said filter portion (110) isdimensioned to extend from an ostium of a first artery for covering anostium of an adjacent artery.
 11. The blood filter of claim 1, furthercomprising a centering hook structure (276) coupled to said anchorportion (42) that projects laterally outward from said anchor portion(42).